How to clean difficult stain in LC-MS/MS Cone?

[biotechno]

Hi everyone,


We been having difficulty cleaning the LC-MS/MS metal cone.

We use standard 45:45:10 methanol/water/formic acid 30 min ultrasound protocol, and some pure formic acid in more difficult ones, but sometimes its just not enough.

We work with liver and urine samples.

Any recommendations for a more efficient cleaning?


Thank you all for your time!

May the science be with you!

[per_oxid]

It is common to use a fine lapping paper to polish away contaminants, we get these from waters and sciex. Waters also have a pencil that is used for polishing. Our service engineer use it also to remove ionburns on the quadropole rods. Just make sure it is of correct specifications so you dont scratch anything, has to be very fine grit. Another aproach is to use a polishing compound with very fine grit, our sciex engineer used a brand called autosol. If you use polishing compound you need to clean it very carefully after of course.

[Gaetan Glauser]

Another very common procedure is to rub it with aluminium oxide q-tip (which ideally should not get pilled). If you have a Waters or Sciex instrument, this is the standard procedure in addition to ultrasound-assisted solvent cleaning.

[biotechno]

Yes, we used to use both to clean the GC-MS source, we still have some around.

Thank you very much for your reply!

.

PS. We know of a dutch lab that uses bathroom CIF cleaning cream (with particles derived from limestone) - sounds crazy to us, but they claim to be wonderful lol

Anyway, we don't have money like they do to replace parts in case it goes wrong so.. not really an option here lol

[JMB]

Q-tip (cotton bud end) with suspension of fine aluminium oxide in glycerol.

Then sonicate as usual to remove Al2O3.

Regards,
JMB

[James_Ball]

Q-tip (cotton bud end) with suspension of fine aluminium oxide in glycerol.

Then sonicate as usual to remove Al2O3.

Regards,
JMB

We normally use the aluminum oxide suspended in Citranox made to the consistency of tooth paste. Citranox or Alconox are recommended as cleaning agents for some of the LCMS manufacturers and it dissolves away easily with water and sonication. Citranox has the added benefit of being slightly acidic. I use it for cones and for the GCMS source. For ICP/MS I have used Bar Keepers Friend to clean those cones, works just as good.